Xnami 1.0 - Cross-Site Scripting

# Exploit Title: Xnami Image Sharing - Persistent XSS Vulnerability
# Google Dork: "  Copyright 2017 xnami. " & 2018
# Date: 11-01-2018
# Exploit Author: Dennis Veninga
# Contact Author: d.veninga [at] networking4all.com
# Vendor Homepage: bizlogicdev.com
# Version: 1.0
# CVE-ID: CVE-2018-5370

Xnami facilitates the creation of an image sharing community. This is
similar in
functionality to sites like imgur, ImageShack, et al.

BizLogic xnami 1.0 has XSS via the comment parameter in an addComment
action to the /media/ajax URI.

At any uploaded media there is a comment system where people can post (also
anonymous).
The comment system is vulnerable to XSS attacks. Since it's persistent
and there is an user login interface, it's possible for attackers to
steal sessions of users and thus admin(s).

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PoC with mediaId 611 as example:

POST:
http://{{target}/media/ajax

method: addComment
comment: "><XSSCODE<
mediaId 611
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Evil javascript code can be inserted and will be executed when visiting the
media.